Greg KH, Linux kernel developer delivered a keynote in the Linux plumbing conference about the health of the ecosystem. His message was essentially that distributions that don't contribute to the ecosystem have to rely on the whims of others which is unhealthy for them. Here is an introduction the development model and some interesting statistics about the Linux kernel code. Update by TH: Rebuttals are appearing all over the web, like this one by Canonical's Matt Zimmerman ("He's refuting a claim which has, quite simply, never been made. [...] When this sort of thing happens on mailing lists, it's called trolling."), or this one by another Canonical employee, Dustin Kirkland.

Well, obviously their GUI and usability work, especially that related to GNOME. You cannot concentrate on everything and be good at it all, you have to concentrate. Although - according to many - Ubuntu is already spreading its focus in all too many directions.

But I suppose there are always people who have nothing better to do than whine, what ever you choose to do...

Also, like many have already pointed out, and Shuttleworth is always ready to admit, Ubuntu is only building on the well-tested Debian base. Lots of the basic work, like the work related to kernel etc. is already done for them by Debian. Debian base is very good and there's no need to reinvent the wheel in that sense. But what Debian lacked, traditionally, was related to its desktop usability, and that is the field that Ubuntu has concentrated on. Why should they reinvent the wheel and start competing with Debian by concentrating on the exact same tasks that Debian already does for them?

If we are talking about open source and free software, why should we support camp mentality, this camp against that camp etc? Co-operation is and should be the key word in the open source world. Contributors to free software are supposed to cooperate with each other instead of competing against each other. Somebody is good at something and concentrates on that and it will benefit the whole community.

Unlike Novell, Canonical is not a big old corporation, and lacks resources compared to Novell. In fact, Canonical's resources are still a bit too much the same thing as Mark Shuttleworth's money that he has generously given to the Ubuntu development. The man is sure rich but he doesn't have endless amounts of money and has his right to decide what kind of projects he sees more important to give money to.

What Usability work? Apart from the press release(s) have they actually done anything?

Huh? Yes, of course they have. Otherwise I would still be using Debian on my desktop right now too, instead of Ubuntu. I love Debian but I love ease of use even more and therefore decided to swicth my main desktop to Ubuntu.

The huge amount of other distributions based on Ubuntu is another testimony to that.

However, many things sponsored by Canonical/Ubuntu are now part of GNOME and Debian too so they are not Ubuntu-only things. But that's is how open source projects are supposed to work. You are not trying to reinvent the wheel but cooperate with others.

These are a direct quotes from Wikipedia:

Ubuntu focuses on usability, including the widespread use of the sudo tool for administrative tasks. The Ubiquity installer allows installing Ubuntu to the hard disk from within the Live CD environment without the need for restarting the computer prior to installation. Ubuntu also emphasizes accessibility and internationalization, to reach as many people as possible.

Wubi allows the distribution to be installed on a virtual loop device requiring no partitioning. Wubi also makes use of the Windows migration tool to import users' settings.

Non-free software is usually unsupported (Multiverse), but some exceptions (Restricted) are made for very important non-free software. Supported non-free software includes device drivers that are necessary to run Ubuntu on current hardware, such as binary-only graphics card drivers.

Also many new things in GNOME desktop environment were first introduced by Ubuntu. And so on.